Feeding and weighing apparatus



ug. 24, 1948. L. s. PETERSEN FEEpmG AND WEIGHING APPARATUS 5- Shees-Sheet 1 4 Filed April 1, 1944 Mw w A mw V/ m 7 Q%\ SAS wso l.. s. PETERsEN FEEDING AND WEIGHING APPARATUS Aug. 24, 1943.

A 5 Sheets-Sheet 2 BY 1m;

Filed April 1, 1944 (f MS A TTO RNEYS A1182 24, 1948. A l.. s. PETERSEN 2,44%594 FEEDING AND wEmmNe APPARATUS A I Filed April 1, 1944 V 5' sheets-Sheet s BY. sa 7a;

ATTORNEYS ug. Z4, 194. L.. s. PE-rERsEN FEDING AND WEIGHING APPARATUS 5 Sheet-Sheet 4 Filed April l, 1944 ENToR ATTORNEY5 Aula ug, 24, 43. L, s, PETERSEN g@ FEEDING AND WEIGHIG APPARATUS Filed April 1, 1944 s sheets-sheet 5 EYS Patented' Aug. 24, i948 ric FEEDING AND WEIGHHNG APPARATUS Application April 1, i944, Serial No. 529,216

Claims. y i

This invention relates to apparatus for feeding material at a constant rate and is concerned more particularly with a novel apparatus for the purpose which provides close control of the feeding rate and is of relatively simple construction. The new feeding apparatus includes a feeding means which receives material from a supply and includes a pair of elements, one of which is fixed and the other movable. These elements cooperate to feed the material and their action is controllable so that the material may be fed at diiferent rates within a range. The material discharged from the feeding means is deposited upon a conveyor, which is connected to a counter-balanced weigh beam and is movable from an initial position as the load upon it varies. The weigh beam operates to hold the conveyor in its initial position when it is carrying a selected load and the Weigh beam and its associated parts may be adjusted to vary the load which the conveyor is to carry without displacement. The action of the feeding means is controlled by mechanism brought into action as the conveyor departs from its initial position, because of feeding under or over the desired rate, `and the control mechanism varies the action of the feeding means to make the necessary correction and cause the conveyor to be restored' to its initial position.

The feeding means employed in the apparatusl may be of various types and may include a fixed trough containing a pusher, the stroke of which is varied to control the rate of feed. Another suitable feeder is of the cradle type, in which the material is deposited upon a swinging cradle from which the material is discharged by a xed blade, the-rate of discharge depending upon the length of the swing ci the cradle. Still another feeder that may be used includes a rotating table upon which the material is deposited from a supply, the material being discharged from the table by a blade which can be moved to dierent positions to vary the feeding rate.

The action of the feeding means may be controlled by electric or pneumatic means actuated by movements of the conveyor and, preferably, operated by means associated with the weigh beam connected to the conveyor and movable thereby. In-one satisfactory form,'the control includes a cylinder and piston, the latter connected to a slide which is movable to different positions, dependent upon the pressure of air admitted into the cylinder. The slide is then connected to an appropriate part of the feeding means for varying the action of the latter.

For a better understanding of the application,

(Cl. Z22-.55)

reference may be had to the accompanying drawings, in which Figure 1 is a view of one form of the apparatus in elevation with parts broken away'and other parts shown in vertical section;

Figure 2 is an end view of the apparatus shown in Figure l seen from the right;

Figure 3 is a sectional view on the line of Figure l.;

Figure t is a sectional view on the line 2i-t of Figure 2; 1

Figure 5 is a view similar to Figure 1 of a modiiied form of the apparatus;

Figure 6 is a fragmentary plan view of the construction shown in Figure 5;

Figure 7 is a view partly in elevation and partly in vertical section of another modied form oi the apparatus; o

Figure 8 is a sectional view on the line -t of Figure 7; and

Figure 9 is a diagrammatic view showing the apparatus equipped with an electrical control mechanism.

The apparatus shown in Figure l includes a casing til having an inlet hopper 2i at the top, through which material from any suitable source of supply is discharged into a trough 22. Within the trough is a pusher 2S mounted on a rod td which extends through the trough from end to end and has one end projecting through a guide 25 in the wall of the housing. The other end of the rod is connected to an arm 2t on a shait El mounted in suitable bearings and provided with an arm 2t connected by a rod 29 to a slide t@ Within a cylinder 3i. The cylinder 3i is provided withl trunnions 32 mounted in bearings in a bracket 33 attached to a suitable part of the apparatus and, in the operation of the device, the cylinder is rocked by an arm 3d attached to a crank t5 on a shaft 36 driven by any suitable means, such as a motor and reduction gear.

Within the cylinder 3i is a rod 3l attached to one end of the slide 36 and extending through an end wall 38 of the cylinder. The rod .is encircled by a spring 39 bearing at one end against the slide and at the other end against end wall 38. Beyond the end wall, the rod carries a disk it within an oil dashpot li. The other end of slide Sii is connected to a piston (not shown) within the cylf pulley 43 on shaft 44 mounted in xed bearings and driven by chain 45 from shaft 36,. Belt 42 is also trained about pulley 48 mounted on a shaft 41 running in bearings mounted adjustably in a frame 48 which is free to swing about shaft 44 as an axis. The material deposited upon the upper stretch of the belt is discharged therefrom to fall through an opening 49 in casing 50 which encloses the conveyor.

The conveyor is normally supported in generally horizontal position by a stirrup 5I attached to the frame 48 and connected by a rod 52 to the end of the short armdof a weigh beam 53 pivoted at 54 in a bracket 55 attached to a suitable part of the' structure. The weigh beam carries a counwardly until its stem engagesv the screw 11. This causes the valve stem to be depressed and the valve opened to admit air into the cylinder.

The valve 51 is actuated by an adjustment screw 19 threaded through a lever 88' pivoted at one end 89 on bracket 55. The free end of lever -88 coacts with a pin 99 of a lever 9| pivotally mounted at 92 on the weigh beam titl. The position of lever 9| on the beam is determined by ter-balancing weight 56 at Vthe end of its longv arm and the weight may be varied so that the beam will support the conveyor in horizontal position under diierent loads. If a change in the l'oad on the conveyor occurs as the result in a change in the specific gravity of the material or for any other reason, the conveyor will either swing downward or upward, as the case may be. This movement ot the conveyor is utilized to control the action of the feeding mechanism.

. The control mechanism illustrated is of the pneumatic type and it includes an air valve 51 mounted on bracket 55. This valve receives air under pressure through a line 58 connected to a source, the connection including a gauge 59 for indicatingthe pressure. The valve includes an inlet 60 leading to a passage 5| inthe body of the valve and the passage leads to a chamber 62 from which there is an outlet passage 63. A ball 64 within chamber 62. is normally forced upwardly by a spring 65 to close the-outlet passage. A rod (iii itting loosely within passage 63 rests on top of the ball. The` rod extends through an outlet chamber 61 from which the air can escape through an outlet 68. The top of the outlet chamber 61 is closed` by a hollow plug 69 into the interior of which the rod 66 projects. A ball 18 rests on the top of rod 66 Within the outlet chamber 61 and closes a passage through a plug 1| threaded into the end of plug B9. A rod 12 rests on top ot ball 10 and by depression of rod 12, the balls can be unseated. In that condition, air under pressure enters through the inlet 68 and iows past ball 64 into the outlet chamber 61 from -Which it issues through outlet 68. Some of the air may also escape around rod 66 and-now past ball 18 to escape around rod 12 through the passage in plug 1|. The amount of air so allowed to escape around ball 18 is a small proportion of the air admitted into chamber 61.

The outlet fitting 68 is connected by aline 13 to a passage within a block 14, which is mounted on one of the trunnions 32 attached to cylinder 3|, and air entering the passage'in block 14 lpasses to an air valve 15 mounted on the block. A line 16 leads from the air valve to an inlet at the end of cylinder 3|. Valve 15 is provided with an operating stem 15 which can be engaged by an adjustment screw 11 on a bracket 18 faston bracket 33. Each time the cylinder 3| is rocked counterclockwise, valve 15 moves upupper and lower adjustment screws 93, 94 mounted in brackets -on the beam'. vThe lever 88 is kept in contact with pin 90 by a spring 95 attached at one end to lcver B8 and at the other to bracket 55. Y

In addition to the counterweight 56, the weigh beam is acted on by a spring 96 encircling a rod 91 which is connected at one end to the weigh beam and extends through a web on a bracket 98 to which bracket' 55 is attached. The spring acts on a nut 99 at .the end of the rod and on the web and tends to move the weigh beam clockwise about its pivot. The movement of the weigh beam in this direction is limited by nuts threaded on the rod and engageable with the undersurface of the web.

In the operation of the apparatus, the weigh beam is set to maintain the conveyor in generally horizontal position under a selected load 'of .material deposited upon the conveyor belt by discharge from trough 22 by pusher 23. Initially, air will have been admitted through valve 51 into cylinder 3| to move slide 30 against the action of spring 39 to a position which will cause the pusher 23 to have the desired stroke. As the material is fed to the conveyor, it is moved along the latter to the discharge and so long as the load on the conveyor does not vary, the conveyor will stay in its initial position. Whenever there is a change in the load, for example, an overload, for any reason, such as an increase in the specific gravity of the material, the conveyor will tend to swing downwardly. This will cause lever 88 to swing counterclockwise so that it will permit the pin of valve 51 to rise and the valve will tend to close. As the shaft lrotates. the cylinder 3| will be rocked once per revolution of the shaft and on each upward movement of the right hand end of the cylinder, valve 15 will be opened. When the opening through valve 51 is reduced, the pressure in line 13 will fall and, whenever valve 15 is opened, air will escape from the end of the cylinder back through line 13 vto valve 5l, from which it will escape around rod 66. As the pressure behind the piston falls, spring 39 will move slide 38 to the right and this will decrease the distance between the axis about which cylinder 3| rocks and the point of connection of rod 29 to slide 30. Such a change in the position of the slide reduces the arc of movement of rod 29 and in turn reduces the stroke of the pusher 23 and the rate of feeding. With a Y reduction in the rate of feed to the conveyor, the

load thereon will diminish until the conveyor will be raised by the action of the weigh beam. As the weigh beam swings clockwise about its pivot, the opening of valve 51 will be increased and air at greater pressu're will enter the cylinder and cause slide 30 to be moved against the action of spring 39. This will result in the increase in the stroke of the pusher 23..

A decrease in the load on the conveyor produces actions of the parts which are the reverse of those described. Under a decreased load, the conveyor will move the weigh beam to cause an increase in the opening of the valve 51,.air under greater 5 pressurelwill enter the cylinder, and the slide 30 will be moved to increase the stroke of the pusher.

The control mechanism, actuated by the movement of the conveyor from its .initial position, may be operated directly or indirectly from the conveyor. Preferably, the control is vactuated from the weigh beam, which is in turn moved by the conveyor as the latter departs from its initial position.

In the construction illustrated in Figures 5 and 6, the feeding mechanism includes a cradle hung from a shaft |02 and adapted to be swung about the axis o f the shaft. A fixed blade |03 cooperates with the cradle. The material enters the feeding means through inlet .|00 into the casing and the material is deposited upon the cradle. As the latter swings back and forth,

a quantity of the material is discharged by the depends upon the arc through which the cradle is swung.

The cradleis actuated by an arm |00 fast on shaft |02 and connected by a rod |07 to a slide within a cylinder |08. The slide and cylinder are of the same construction asA slide 3|) and cylinder 3| and the cylinder is pivoted at |09 on a bracket ||0. The cylinder is attached by a rod I to a crank on shaft ||2 which is driven by a motor |I3 through a worm drive.

The material discharged from the cradle |0| is deposited upon a conveyor H0, which is similar to the conveyor illustrated in Figure 1 and includes a conveyor belt I I5 trained abouta pulley on shaft I6 driven from shaft ||2 by chain Hl. The conveyor is connected by a rod H8. to-one end of a weigh beam |9, the other end of the beam carrying a movable weight |20. Attached to the beam is an arm |2| carrying a pin |22 on which bears a lever |23 carrying an adjustment screw |24 in position to make contact with the stem of an air valve |25. As the weigh beam moves in response to a departure of the conveyor from its initial position as a result of a variation in the load the lever |23 varies the opening of the air valve |25 and thus controls the pressure of air in a line |25 leading to the top of cylinder |08. The movement of the weigh beam is restricted by an arm |21 which lies between adjustment screws |28 mounted in a suitable bracket.

` In the operation of the device illustrated in Figures 5 and 6, the cradle is rocked back and forth by the swinging of the cylinder |00 on its pivot. Such movement of the cradle causes material to be discharged on the conveyor and the rate of feed depends on the stroke of the cradle. This stroke is determined by the distance between the slide within cylinder |00 and the point |09 about which the cylinder is rocked. When the rate of feed is too high and the load on the conveyor increases, theA conveyor moves from its initial position and this causes a movement of the weigh beam which in turn causes a change in the opening of air valve |25.- As the air supplied to cylinder |00 increases or decreases, the slide moves farther from or nearer to the pivot. |09 and this changes the stroke of the cradle.

In the construction shown in Figures 7 and 8, the feeding device includes a casing |29 through which material is discharged upon a' rotating table |30. The material is removed from the table by means of a scraper blade |3| and discharged thereby through a chute |32 upon the belt |33 of a conveyor. The conveyor is connected to a weigh beam |34 similar to the beam 53 (Figure 1) and when the conveyor falls or rises in response to an 6 increase or a decrease in the load thereon. the weigh beam is correspondingly swung. An air valve |35 is actuated by a lever |36, as the weigh beam swings in one direction or the other, and the valve controls the pressure of air admitted through a line |37 into a cylinder |38. The piston |39 in the cylinder is connected to a rod |40 which is in turn connected to the blade |3|. A tension spring connected at one end to rod |00 and at the other end to the end |02 of the cylinder tends to pull on the rod |40. As the conveyor moves down under an increase in load, air under higher pressure is admitted to the cylinder |39 and moves the piston to cause blade |3| to swing clockwise. This decreases the rate at which material is fed upon the conveyor. When a decrease in the load upon the conveyor occurs, the air pressure within the cylinder decreases and spring MI is then effective to swing blade I3| counterclockwise to increase the rate of feed.

The construction illustrated in Figure 9 includes an electrical control mechanism for controlling the operation of the feeding means in accordance with variations in the load on the conveyor, the feeding means shown being of the pusher type illustrated in Figure 1. The Figure 9 apparatus includes a conveyor |03 including a belt driven from a shaft |04, the conveyor being connected to a weigh beam |05 which may be counter-balanced to support the conveyor in generally horizontal position -when it is carrying a selected load. A movable contact |00 forming part of a switch |01 is actuated by the weigh beam and is movable by the latter into engagement with one or the other of the contacts Ma, |581. The contacts are connected through a motor-driven time delay device |09' of conventional construction to a reversing starter which is connected to a source of power through lines |5| and is also connected through lines |52 to a motor |53.

The motor acts' through a reducing device |50 to drive a screw |55in a cylinder |55. The cylinder |55 is pivotally mounted at |57 and, during the operation of the device, is rocked by a crank |50 acting through a link |59. The pusher-element |00 of the feeding means is connected through a rod |0| and crank |02 to a shaft |53 which carries a crank connected by rod |05 to a nut |50 threaded on the screw |55 within the cylinder |55. The stroke of the pusher |00 depends on the position of the nut |66 with relation to the pivot |5`| about whichcylinder |56 is rocked.

In the operation of the device shown in Figure 9, the weigh beam is counter-balanced to support the conveyor under a selected load and when a variation in the load occurs, the conveyor moves up or down, as the case may be. ySuch movement of the conveyor is transmitted to the beam and causes contact |46 to engage one or the other of the contacts |0811 and |481). The engagement of vthe contacts establishes a circuit which, after an interval determined by the time delay device |49, causes the reversing starter |50 to start motor |53. The motor then operates through reducer |5-| to rotate screw |55 and this causes the nut |66 to move lengthwise of the cylinder to alter the position of the nut relative to the point |57 about which the cylinder is rocked by crank |58. The movement of the nut thus increases or reduces the stroke of the pusher 'as may be required to alter the action of the feeding meansto correct the rate of feed.

IThe electrical mechanism illustrated in Figure 9 is one advantageous arrangement for control- 7 ling thel feeding means in response to variation in the load on the conveyor but it will be apparent that various other electrical .expedients may be used for the purpose. The time delay device is desirable, because it prevents the control mechanism from responding to minor variations in the load and thus reduces the periods during which the motor |53 is in operation. A suitable time delay device will be used to cause the .control AAJmechanism to operate with the desired sensitivity and without undesirable hunting.

I claim:

1. Apparatus for supplying material at a constant rate, which comprises material feeding means including a pair of elements, one of which is stationary and the other of which reciprocates, and mechanical means for reciprocating the second element to effect feeding of the material, a conveyor receiving material from the feeding meansand movable from an initial position as the load thereon varies, a weigh beam connected to the conveyor and operable to hold it in said initial position when it is carrying a selected load, said beam being movable by the conveyor as the latter changes position in response to varying loads, and means operated by the conveyor as the latter moves from its initial position for acting on the means for reciprocating the second element to vary the length of the stroke thereof. j

2. Apparatus for supplying material at a. constant rate, which comprises material feeding means including a pair of elements, one of which is stationary and the other of which reciprocates, and mechanical means for reciprocating the seeond element to eiect feeding of the material, a conveyor receiving material` from the feeding means and movable from an initial position as the load thereon varies, a Weigh beam connected to the conveyor and operable to hold it in said initial Dositon when it is carrying a selected load, said beam being movable by the conveyor as the latter changes position in` response to varying loads, and fluid control means operated by the conveyor as the latter moves from its initial position for acting on the means for reciprocating the second element to vary the length of the stroke thereof.

3. Apparatus for supplying material at a constant rate, which comprises material feeding means including a pair of elements, one of which is stationary and the other of which reciprocates, and mechanical means for reciprocating the second element to eifect feeding of the material, a conveyor receiving material from the feeding means and movable from an initial position as the load thereon varies, a weigh beam connected to the conveyor and operable to hold it in said initial position when it is carrying a selected load,

said beam being movable by the conveyor as the latter changes position in response to varying loads, means operable on the means for reciprocating the second element to vary the length of the stroke thereof, and means controlled by the conveyor as it moves from its initial position and controlling the action of the stroke varying` means.

4. Apparatus 'for supplying material at a constant rate, which comprises material feeding means including a pair of elements, one of which is stationary and the other of which reciprocates, and means for reciprocating the second element, a conveyor receiving material from the feeding means and movable from an initial position as the load thereon varies, a weigh beam connected to the conveyor and operable to hold itin said Yinitial position when it is carrying a selected iluid to the fluid meansand operated by the con veyor as the latter moves from its initial position.

5. Apparatus for supplying material at a constant rate, which comprises feeding means including a pair of elements, one of which is stationary and the other of which reciprocates. ar..A means Vconnected to the second element for reciprocatlng it, the connection including a cylinder mounted for rocking movement and a piston within the cylinder and connected to the reciprocating element, the position of the piston within the cylinder determining the stroke of the element, a conveyor receiving material from the feeding means and movable from an initial position as the load thereon varies, a weigh beam connected to the conveyor and operable to hold it in an initial position when it is carrying a selected load, the beam being movable by the conveyor as the latter changes position in response to varying loads, a supply of fluid under pressure connected to the cylinder, and a valve controlling the flow of fluid to the cylinder and operated by the conveyor as it moves from its initial position.

6. Apparatus for supplying material at a constant rate, which comprises feeding means including a pair of elements, one of which'is stationary and the other of which reciprocates, and means connected to the second element for reciprocating it, said means including an arm, a slide connected to the arm, and means for rocking the slide about an axis, the slide being movable toward and away from the axis to vary the stroke of the reciprocating element, a conveyor receiving material from the feeding means and movable from an initial position as the load thereon varies, a Weigh beam connected to the conveyor and operable to hold it in an initial position when it is carrying a, selected load, and'means controlled by the movements of the conveyor in response to changes in the load for moving the slide to vary the stroke ofthe reciprocating element.

'7. In apparatus for supplying material at a constant rate, said apparatus including a conveyor movable from an initial position as the load thereon varies, means for feeding material to the conveyor including a stationary element, a reciprocating element, a slide connected to the reciprocating element, means for rocking the slide about an axis to reciprocate the reciprocating element, the slide being movable toward and away from the axis to vary the stroke of the reciprocating element. and means responsive to changes in position of the conveyor for moving the slide.

8. In apparatus for supplying, material at a constant rate, said apparatus ,including a conveyor movable from an initial position as the load thereon varies, means for feeding material to the conveyor including a stationary element,

a, reciprocating element, a slide connected to the constant rate. said apparatus including a conveyor movable trom an initial position as the load thereon varies, means for feeding material to the conveyor including a stationary element. a reciprocating element. a slide connected to the reciprocating element, means for rocking the slide about an axis to reciprocate .the reciprocating element, the slide being movable toward and away from the axis to vary the stroke of the reciprocating element. and pneumatic means responsiveA to changes in position of the 'conveyor for moving the' slide. said means including a cylinder. a

piston within the cylinder and connected to the slide, a supply oi air under pressure. anda valve operated by the conveyor as it moves from its initial position for controlling the flow of air to the cylinder to act on the piston.

10. In apparatus for supplying material at a constant rate. said apparatus including a conveyor movable from an initial position as the load thereon varies, means for feeding material to the conveyor including a stationary element,

a reciprocating element. a member rockable aboutan asis` means for rocking the member. means connected to the member transmitting the move- REFERENCES man The following references are oi record in the ille oi this patent:

UNITED s'rA'rss PATENTS Number Name Date 771,764 Bousser Oct. 4, 1904' 1,125,705 Messiter Jan. 19, 1918 1,558,668 Carter Oct. 27. 1926- 1,755,103 Davis Apr. 15, 1930 1,992,716 Paxton Feb. 26, 1935 .2,164,796 Bird July 4, 1939 2,184,812 Francis et al. July 4, 1939 2,206,237 

